Display ProgressBar in Android

Karan Balkar

Hey everyone!

A ProgressBar is basically a visual indicator of progress in some operation. Implementing a ProgressBar helps in the understanding of processes running on threads separate from the main User Interface (UI) and the communication between threads. As mentioned on the Android developer's page, a progress bar can also be made indeterminate. In indeterminate mode, the progress bar shows a cyclic animation without an indication of progress. This mode is used by applications when the length of the task is unknown.

By default the progress bar is a spinning wheel (an indeterminate indicator). We can always change to a horizontal progress bar using the Widget.ProgressBar.Horizontal style as follows,

<ProgressBar
     style="@android:style/Widget.ProgressBar.Horizontal"
     ... />

Through this post, we will learn how to display a ProgressBar in Android.

Pre-requisites: Android SDK

Create a new Activity class called MyProgressBarActivity in any of your existing Android projects and add the following code!

MyProgressBarActivity.java

package com.example;

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;

public class MyProgressBarActivity extends Activity {

	private ProgressBar progBar;
	private Handler mHandler = new Handler();;
	private int mProgressStatus = 0;
	private Button showProgressBar;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		progBar= (ProgressBar)findViewById(R.id.progBar1);
		showProgressBar= (Button)findViewById(R.id.btn1);
		showProgressBar.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				doSomeWork();
			}
		});

	}

	public void doSomeWork(){

		// Start lengthy operation in a background thread
		new Thread(new Runnable() {
			public void run() {
				while (mProgressStatus < 100) {
					mProgressStatus += 1;
					// Update the progress bar
					mHandler.post(new Runnable() {
						public void run() {
							progBar.setProgress(mProgressStatus);
						}
					});
					try {
						//Display progress slowly
						Thread.sleep(200);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			}
		}).start();
	}
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
    <TextView
        android:id="@+id/txt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/btn1"
        android:layout_below="@+id/txt1"
        android:text="@string/show"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    
       <ProgressBar
         android:id="@+id/progBar1"
         android:layout_below="@+id/btn1"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         style="@android:style/Widget.ProgressBar.Horizontal"
         android:layout_marginRight="15dp" />
        
</RelativeLayout>

Run the Android application by specifying the above Activity as the default launcher Activity and you should see the ProgressBar in action! :)